Conventional electric water heater tanks include a heating element operable to heat water stored within the tank. The heating element is mounted to a water tank flange that protrudes from an external surface of the water tank. The heating element includes an internal portion that extends into at least part of the tank interior and an external portion that protrudes from the water tank flange.
A mount is secured to the external portion of the water tank flange. In conventional electric water heater tanks the mount directly supports a temperature control thermostat. The temperature control thermostat includes a bimetal disc that is in contact with the exterior surface of the water tank. The bimetal disc undergoes physical changes in response to changes in the temperature of the water in the tank.
A high-limit thermostat is mounted directly to the control thermostat. The high-limit thermostat prevents the heating element from heating the water above a predetermined high-limit temperature. The high-limit thermostat includes a bimetal disc that is in contact with the exterior surface of the water tank. When the temperature of the water within the tank increases above the predetermined limit, the bimetal disc undergoes a physical change. In response to this physical change, the high-limit thermostat opens a switch that deactivates the heating element.
While conventional temperature control thermostats are suitable for their intended uses, they are subject to improvement. For example, bimetal temperature control thermostats are being replaced with electronic temperature control systems on an increasing basis. Electronic temperature control systems provide enhanced temperature control, as well as numerous other features.
In some electronic control systems, the temperature control thermostat is replaced with an electronic control unit and a sensor probe. The sensor probe is typically mounted at the exterior surface of the water tank. The sensor probe transmits signals to the control unit indicative of the temperature of the water within the tank. The control unit processes the signals from the sensor probe and controls the heating element, as needed, to bring the water to a desired set-point temperature, which is established by programming the control unit.
Because the bimetal temperature control thermostat, which conventionally supports the high limit thermostat, is not used in electronic temperature control systems, there is a need in electronic control systems for a device to support the high limit thermostat at the exterior surface of the water tank. There is also a need for a device to mount the sensor probe at the external surface of the water tank.